NOAA: Scientists Find 20 Years of Deep Water Warming Leading to Sea Level Rise
Sea-level rise has the potential to reshape the coastal environment. Credit: NOAA)
Scientists analyzing measurements taken in the deep ocean around the globe over the past two decades find a warming trend that contributes to sea level rise, especially around Antarctica.
Greenhouse gases in the atmosphere, such as carbon dioxide, cause heating of the Earth. Over the past few decades, at least 80 percent of this heat energy has gone into the ocean, warming it in the process.
“Previous studies have shown that the upper ocean is warming, but our analysis determines how much additional heat the deep ocean is storing from warming observed all the way to the ocean floor,” said Sarah Purkey, an oceanographer at the University of Washington and lead author of the study.
This study shows that the deep ocean – below about 3,300 feet – is taking up about 16 percent of what the upper ocean is absorbing. The authors note that there are several possible causes for this deep warming: a shift in Southern Ocean winds, a change in the density of what is called Antarctic Bottom Water, or how quickly that bottom water is formed near the Antarctic, where it sinks to fill the deepest, coldest portions of the ocean around much of the globe.
The scientists found the strongest deep warming around Antarctica, weakening with distance from its source as it spreads around the globe. While the temperature increases are small (about 0.03°C per decade in the deep Southern Ocean, less elsewhere), the large volume of the ocean over which they are found and the high capacity of water to absorb heat means that this warming accounts for a huge amount of energy storage. If this deep ocean heating were going into the atmosphere instead – a physical impossibility – it would be warming at a rate of about 3°C (over 5°F) per decade.
“A warming Earth causes sea level rise in two ways,” said Gregory Johnson, a NOAA oceanographer at the Pacific Marine Environmental Laboratory in Seattle, and the study’s co-author. “The warming heats the ocean, causing it to expand, and melts continental ice, adding water to the ocean. The expansion and added water both cause the sea to encroach on the land.”
Sea level has been rising at around 3 mm (1/8 of a inch) per year on average since 1993, with about half of that caused by ocean thermal expansion and the other half because of additional water added to the ocean, mostly from melting continental ice. Purkey and Johnson note that deep warming of the Southern Ocean accounts for about 1.2 mm (about 1/20th of an inch) per year of the sea level rise around Antarctica in the past few decades.
The highly accurate deep-ocean temperature observations used in this study come from ship-based instruments that measure conductivity through salinity, temperature and depth. These measurements were taken on a series of hydrographic surveys of the global ocean in the 1990s through the World Ocean Circulation Experiment and in the 2000s in support of the Climate Variability program. These surveys are now coordinated by the international Global Ship-based Hydrographic Investigations Program.
The study, “Warming of Global Abyssal and Deep Southern Ocean Waters between the 1990s and 2000s: Contributions to Global Heat and Sea Level Rise Budgets,” authored by Sarah G. Purkey and Gregory C. Johnson, will be published in an upcoming edition of the Journal of Climate.
NOAA’s mission is to understand and predict changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Find us on Facebook.
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Here is the abstract:
2 NOAA/Pacific Marine Environmental Laboratory, Seattle WA 98115, USA
| Abstract |
|---|
We quantify abyssal global and deep Southern Ocean temperature trends between the 1990s and 2000s to assess the role of recent warming of these regions in global heat and sea level budgets. We compute warming rates with uncertainties along 28 full-depth, high-quality, hydrographic sections that have been occupied two or more times between 1980 and 2010. We divide the global ocean into 32 basins defined by the topography and climatological ocean bottom temperatures and estimate temperature trends in the 24 sampled basins. The three southernmost basins show a strong statistically significant abyssal warming trend, with that warming signal weakening to the north in the central Pacific, western Atlantic, and eastern Indian Oceans. Eastern Atlantic and western Indian Ocean basins show statistically insignificant abyssal cooling trends. Excepting the Arctic Ocean and Nordic seas, the rate of abyssal (below 4000 m) global ocean heat content change in the 1990s and 2000s is equivalent to a heat flux of 0.027 (±0.009) W m−2 applied over the entire surface of the Earth. Deep (1000–4000 m) warming south of the Sub-Antarctic Front of the Antarctic Circumpolar Current adds 0.068 (±0.062) W m−2. The abyssal warming produces a 0.053 (±0.017) mm yr−1 increase in global average sea level and the deep warming south of the Sub-Antarctic Front adds another 0.093 (±0.081) mm yr−1. Thus warming in these regions, ventilated primarily by Antarctic Bottom Water, accounts for a statistically significant fraction of the present global energy and sea level budgets.
Received: February 16, 2010; Revised: July 28, 2010; Revised: August 18, 2010
*Pacific Marine Environmental Laboratory Contribution Number 3524.
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These guys have a fixation with sea levels….guess they need some “water boarding” 🙂
It is a CO2 Bucket Brigade! The little CO2 critters have buckets they use to capture the warmth and pass it off toe others until they pour the warmth out on the ocean floor. Remember that CO2 critters move at almost the speed of light that is why us mortal humans rarely see them. 😉
“The warmth disperses as it moves away from the source.”
Seeing as we now have some credible science that proves that CO2 is warming the oceans, I believe it’s time for me to roll-out my new Carbon Capture and Storage business. CO2 spa and pool heaters! Not only can you charge companies for the storage of their nasty CO2 but you can also sell your own Carbon Credits that you’ll earn from shutting-off your electric or gas pool heaters! This is a no-brainer. Mabel… get David Suzuki on the line!
Alan Clark of Dirty Oil-berta says:
September 26, 2010 at 6:14 pm
Seeing as we now have some credible science that proves that CO2 is warming the oceans, I believe it’s time for me to roll-out my new Carbon Capture and Storage business.
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Let me guess, We Be Co2 Pooper Scoopers?
I. “Greenhouse gases in the atmosphere, such as carbon dioxide, cause heating of the Earth. Over the past few decades, at least 80 percent of this heat energy has gone into the ocean, warming it in the process.”
II. “NOAA’s mission is to understand and predict changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. ”
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Hey NOAA, If your mission is to freaking “understand” it, then how can you be so stupid to betray that mission by allowing such utter nonsense in paragraph I above to be published??
Taxpayer-funded hubris!
Chris
Norfolk, VA, USA
In all of this discussion, do keep in mind that a thermal expansion or contraction of the whole ocean mass, causing either a rise or fall in surface level, is dependent upon the whole mass of the sea undergoing temperature change. The rider is that an abundance of measurements made from surface to 700 m depth have little place in the mathematics unless they are matched by a similar sampling density at all depths.
That is, it’s insufficient to show that there is an expanding hot spot somewhere. It is also required to show that there is no compensating cooling spot somewhere else – measured with equal micrometer precision, to borrow from the engineering quote of R T Barker above.
OK, OK, OK. Now lettuce think about this fer a minute.
Temperature (heat energy) goes from higher to lower. Never the opposite.
So if an air temperature (on average) over the whole globe goes up by 1/2 of one degree C, but transmits that energy into seawater and land that are 1000 more heat capable (specific heats compared of air, water, and ground/rock compared in comparable units that is) then the air or water will be able to heatup only 1/1000 as much as the air. (Energy out from the air = energy in to the ground/water)
Fine. Makes sense. So far.
Then, if this is “energy in the pipeline” and is so much feared by the CAGW propagandists then how will this energy be expressed?
At best, then the final ground and water temperature will be 0.5 degree x 1/1000 = 0.0005 degree change in final temperature of the earth for today’s temperature changes.
Then, since we expect the 2000-2030 timeframe to be even or reducing temperatures from now (based on a known and predictable 60 year climate cycle rising from the 1970 low point), what will the final temperature of the earth be at 2060?
0.0000 from now.
And, IF (big “if”) the Modern Warm Point peak is later (at 2060-2070, rather than today’s 2000-2010 peak) we might be a 0.0010 final temperature increase. Gee.
Roger Sowell;
I was going to go all sarcastic on you but then read the additional discussion about solar ponds and IR and decided to go a different route. You’ll find my sarcasm gene unleashed in my next comment.
You are correct that IR from the Sun and IR from CO2 behave the same. They BOTH get absorbed in the first few microns of water and then get taken back into the atmosphere via evaporation. CO2 however ONLY radiates in the IR spectrum (at least at normal earth temperatures) while the Sun radiates IR and a broad spectrum of shorter wave lengths. It is the shorter wavelengths that penetrate water deep enough to make your solar ponds work.
Just look at http://en.wikipedia.org/wiki/File:Thermocline.jpg . Ask yourself, what would happen to this curve if more energy was added to the top 100 m of the oceans (warming ocean). I think you will answer that yourself. What if you remove energy from the top 1 meter of this curve (cooling ocean).
Now look how NOAA conveniently leaves out the lower layers of the graph with its nearly vertical temperature profile. Doing that you can paint some very misleading views.
http://oceanservice.noaa.gov/education/yos/resource/JetStream/ocean/layers_ocean.htm
Now, apply that knowledge to this article.
Dave Wendt says:
September 26, 2010 at 3:50 pm
http://www.ocean-sci.net/5/203/2009/os-5-203-2009.pdf
Are you sure the link given is live?
I went to it & found nothing.
We quantify abyssal global and deep Southern Ocean temperature trends between the 1990s and 2000s to assess the role of recent warming of these regions in global heat and sea level budgets. We compute warming rates with uncertainties along 28 full-depth, high-quality, hydrographic sections that have been occupied two or more times between 1980 and 2010 .
Datasets allowing for measurements made as infrequent as two or more times during a thirty year period would be considered inadequate elsewhere but in “Climate Science” it is all too common for this to be termed “ROBUST” . The sad state of affairs in “Climate Science” forces me to wonder among other things whether or not all datasets with two or more measurements over the thirty year period were even included and what other criteria was considered to qualify the data.
Pochas;
You suggested that the question should not be why are the oceans warming, but why are they so cold in the first place? I have been pondering that question for about an hour now, and I believe I may have discovered the answer, or at least a testable theory.
I have taken the last 100 years of air temperature data and found a direct correlation with the number of politicians and climatologists pontificating on global warming. There have been frequent accusations from skeptics regarding the spewing of hot air by these two groups in particular, but to my knowledge no studies have been undertaken to attempt to quantify the volume or effect on global air temperatures.
However, as Ponchas points out, the oceans are very cold at depth, and I could not help but observe that politicians and climatologists are nearly nonexistant in these areas. I believe a simple experiment could be conducted with various quantities of experts from these professions being weighted down and dropped in varying numbers at different points in the ocean to determine if any significant warming occurs. Alas, upon researching the details for my experiment, I learned that there is no known species of politician or climatologist that can breath sea water. I have my doubts as I have seen these subsets of humanity evolve their personal belief systems on a wide variety of issues in a matter of minutes, often in response to known evolutionary drivers such as opinion polls, and I see no reason to conclude that they cannot convert their output from hot air to hot water. I am assured however, that hot water is something politicians in particular frequently get into, but they are none the less incapable of breathing it. Climatologists on the other hand, have little or no reputation for getting into hot water, they are protected from such hazards by having themselves frequently white washed.
I’m very upset that I cannot find a way to perform my experiment. In particular, I wanted to personaly test the results using multi-purpose specimens, these being specific members of the sample study who claim membership in both groups. It was my expectation that Al Gore, for example, would, would have a larger effect on water temperature than either a climatologist or a politician. Alas, upon investigation it turned out that Al Gore is not a real scientist, nor is he a real politician. (For the purpose of my study, “has beens” don’t count). My understanding is that Al Gore has only been posing as both, and is actually a member of a different profession known as charlatans.
While I have not been able to come up with a way to conduct my experiment, I still believe my theory is accurate as the absence of politicians and climatologists at these ocean depth correlates exactly with not just temperature, but stability also. Having no prospect of measurements being available now or in the near future, I turned instead to computer modeling. I created 12,642 different models, one of which agreed with my theory exactly, and I have deleted the other 12,641.
The only flaw in my model is that upon testing Al Gore, no amount of cement seemed sufficient to overcome the bouyancy due to his massive ego which seemed to be, in fact, filled with hot air. A similar effect occured when testing Michael Mann although the model showed that the bouyancy was due to an ego inflated with methane, not simple hot air. This at first confused me as I did not understand the origin of such large quantities of methane. I have now learned where methane comes from, and my supposition is that professor Mann is full of it.
Jeff L says:
September 26, 2010 at 8:30 pm
Dave Wendt says:
September 26, 2010 at 3:50 pm
http://www.ocean-sci.net/5/203/2009/os-5-203-2009.pdf
Are you sure the link given is live?
I went to it & found nothing.
I checked it and it works for me, not sure what the problem is.
Just finished reading and saved to documents folder of PDF’s from WUWT total of 209 now. Great source of reference material now when I can’t get to a national reference library.
“Thanks for all of the fish”
This is a classic case of the Alarmists like the NOAA desperately trying to find an excuse for their failed hypothesis.
THE ATMOSPHERE CANNOT WARM THE OCEANS..PERIOD.
if it could, then since it’s been over 10,000 years since the height of the last ice age, the oceans should have warmed to the same temp. as the atmosphere by now. It hasn’t.
Those who want the truth about this subject can do themselves a favour and read THIS from the late great John L Daly. It’ll take 3 minutes.
I’m so tempted to call the wags at the NOAA liars and frauds, but I’ll hold fire for a while yet.
Correct me if I’m wrong, but the T of deep water is around 1-2DegC.
Below 4 DegC, water expands as it cools, ergo, it shrinks as it warms.
So if the deep water HAS WARMED zero point something DegC, it cannot possibly add to sea level rise. If anything, it should detract from sea level rise.
p.s. Anyone wishing to learn about why the atmosphere CANNOT warm the oceans, READ HERE. It’ll take 3 minutes.
p.p.s. mods. Rather than delete my last comment, snipping a couple of words might have been in order. But it’s your blog.
ooops there is my comment now. Seems I was a bit rash.
My apollogies to the mods. Sorry
David Hoffer @ur momisugly 8:57,
Hopefully you are going to submit this to a journal.
The best hypotheseis yet!
I see this article is from the Journal of Climate.
So I presume that it is PEER reviewed.
Remind me, someone please,
What do the PEERS do when they do PEER review?
Check the spellllling perhaps or wot?
(Obviously this is not a peered reviewed blog).
Ray says: September 26, 2010 at 8:46 am
Since when warm water is denser than cold water?
I’m afraid its true, I just looked it up. Water that is between the temperature of 3.98 °C and 0 °C exhibits this behaviour of becoming denser as it warms up. (Note that the opposite is true for temperatures outside of this range.)
I wonder how much of the worlds oceans fall within these temperature ranges. When these cold waters warm up this would actually DECREASE sea levels.
There is surely no mystery as to how surface heat is getting to the lower layers. Heat will flow from warm to cool and ocean currents, the ‘conveyor’ system, will cause mixing over time. the rest of the surface heat will radiate away when atmospheric temperatures have fallen below that of the sea’s surface, ie. at night.
Anyway Trenberth’s heat is the heat in the mid troposphere from the GHG’s. This heat is not there because the theory of GHG’s is wrong.
Ray says:
September 26, 2010 at 8:46 am
Since when warm water is denser than cold water? Looks like they never did the hot/cold colored water experiment… only NOAA can make changes to the physics of things and understand why things work in reverse in their world!!!
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Errr no. It means that the water has absorbed heat so it is LESS cold. It does NOT mean that it is warm water.
It’s a good idea to think carefully before accusing other people of being stupid.
Chris H says:
September 26, 2010 at 8:53 am
Have they put the cart before the horse? They attribute the deep ocean warming to rising atmospheric CO2. Is it not just as likely that something else caused the deep ocean warming and the CO2 rise simply represents the deep ocean de-gassing?
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On the balance of evidence it’s not equally likely. Conceptually, whether the oceans are absorbing or releasing net CO2 depends on the partition coefficient for CO2 between air and sea water (which is temperature dependant) and the actual concentrations of CO2 in both air and sea water.
I am going to make a wild guess and suggest that all of these quantities have been measured as well as related parameters such as sea water pH trends..
http://en.wikipedia.org/wiki/Geoid
Stephen Wilde says:
September 26, 2010 at 2:23 pm
DCC said:
“So you are saying that warming surface water over the southern hemisphere causes it to expand and flow south where it is cooled and drops to great depth where it is still warmer than the water it displaces? ”
No,no,no.
The paper starts with a discussion of unexpected warmth at lower levels which got there from an unknown mechanism. We are not discussing surface waters at all.
Solar shortwave penetrates the ocean surface to a couple of hundred metres and they describe a finding whereby it has somehow gone even deeper. It is that deeper warmed water which is implicated in thermohaline circulation movements.”
Must be a really unknown method of heat transportation, as it by passed the argo measured dea depths, and then reappeared in the deeper ocean.
“Must be a really unknown method of heat transportation, as it by passed the argo measured dea depths, and then reappeared in the deeper ocean.”
Clearly, but if they say it’s there then either we ignore them or start looking into it.
I’m not sure that relying on the rather limited Argo results in order to announce that energy transfer into deep waters is impossible constitutes open minded science.
Anyway conduction, upward and downward convection and horizontal drift all conspire to shift energy around. We may be talking large amounts from the point of view of air but it’s miniscule stuff in terms of oceanic heat carrying capability.